Elastic-fluid turbine.



'E. THOMSON ELASTIC FLUID TURBINE.

APPLICATION FILED SEPT.12, 1907.

. Patented Mar-29,1910.

witnesses:

' Inventor; Elihu Thmaon MAM? uNrrEn sTATEs PATENT OFFICE.

mu THOMSON, or swmrsooTT, MASSACHUSETTS, ASSIGNOR To GENERAL ELEcTnio COMPANY, A CORPORATION or NEW YORK.

. ELASTIC FLUID TURBINE.

essay.

To all whom it may concern Be it known that I, ELIHU THOMSON, a

citizen of the United States, residing at Swampscott, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Elastic-Fluid Turbines, of which the following is a specification. i

The present invention relates to elasticfiuid turbines and more especially to those wherein low pressure motive fluid acts upon oppositely rotating bucket wheels.- In a turbine of this character working, for example, between atmos heric pressure and a vacuum equal to 29' of mercury, it is a serious problem to handle the large volume of'fliiid without choking or retarding it on the one hand or abstracting less than the maximum amount of energy on the other.

In carrying out my invention the turbine is so constructed that the .direction of steam flow is radial and inward toward the shaft,

suitable nozzles being provided for directing and guiding the fluid. The nozzles may be --diverging or non-diverging in character,

usually the latter, and are supported by the casing of the machine,the latter containing a circumferential steam chamber 0 ening into the nozzles and receiving. fluid rom a suitable inlet. The bucket wheels are .neste'd one within the other with the proper clearance between, each wheel having its own shaft. It is evident in such a turbine that the buckets must be of considerable len th to accommodate the large volume of motlve fluid at the low pressure. Since the buckets extend parallel to the axis it follows that if they are supported at one end only they will bend outwardly under centrifugal force, at the other, and in rotating will be injured or destroyed either by contacting with a stationary art of the machine or with another row of uckets. To prevent this, the ends of the row of buckets having the greater diameter are securely anchored to the wheel or other carrier, and at their outer or overhanging ends are secured to ,a means braced a amst the effects of centrifugal forcewhich a lows the parts to freely rotate but which revents the pitch diameter of the buckets the shaft carrying the inner wheel,,but 1S separated therefrom bya clearance so that the rotation of one wheel creates .no gmeehanical friction on the other" wheel or its at- I Specification of Letters Patent. Patented lvIar. 29, 1910.

Application filed September 12, 1907'. Serial No. 392,445.

tached parts. It is important to separate theparts in this manner because each has a fairly high surface speed and since the movements are equal and in opposite directions any friction would be the equivalent of one part traveling at twice the speed. To lighten the outer member as much as possible andto permit the exit of steam, the said means is made up of a ring locked to the bucket carrier, a hub surrounding the shaft with a clearance between surfaces and a pluralityof'radial spokes. The inner wheel is also provided with a holding means comprising a peripheral ring, radial spokes to increase In the accompanying drawing which illustrates one of the embodiments of my invention, Figure l is a partial axial section of a turbine; and Fig. 2 is a partial cross section of the same.

1 indicates the casing which is divided into suitable parts in any desired plane or planes. It is provided with an annular steam chamber 2, an inlet conduit 3 and an exhaust conduit 4'. Cast into the casing are sheet metal partitions'o forming walls of the nozzle passages, the other walls being formed by the casing itself. 'These nozzles or nozzle passages receive steam from the chamber 2 and discharge it at the desired velocity and in the proper direction against the adjacent row of wheel buckets. Located within the casing is a bucket wheel 6 mount- .ed on a shaft 7 carried by a bearing in the casing of the machine. Near the periphery of the wheel is an annular row of buckets 8 which extend arallel to the axis. These buckets are united on the end opposite the wheel web by a ring 9. In the present in stance the buckets are cast into the wheel, web and rin but they may be secured in any other manner if desired. Such a ring will not ofitself withstand the strains to whichit would be subjected. In order to prevent the rin 9 from breaking under centrifugal strains and permitting .the bucketsto strike the rozzles, a retaining means is provided, and between the "two is a shoulder to take the strain oil of the re taining bolts 11, shown in dotted lines. The retainer is provided with a hub 12 that is separated frointhe shaft 13 of the second Wheel by a clearance sut'tlcient to keep the parts out of contact at all tunes 'Connecting t e hub With-the outer portion of the ietau is" a-plurality of radial spokes Ll.

These spokes may be cast integral with the hub and outer chamber, or they may be made sc and secured thereto, dependrvice for which the turbine is SllDWEl in 2.

Zi h king,

v within the first mentioned 15 carried by the shaft 13 opposite direction to the said outer wheel. It is provided i an annular. row or buckets 16 extending parallel to the axis. These bucket-s are similar in and rotating in 'ne a construction to those of the first wheel except that they are oppositely disposed as Steam from the nozzles strikes the outer row of buckets and-produces rotation thereof in one direction, and the steam escaping therefrom is directed against the buckets of the inner Wheel and produces rotation thereof in the opposite direction, The right hand endsot the buckets are secured to a retainer 17 and the latter is connected by spokes 18 with the hub 19. In this particular instance the buckets 16 are cast into the wheel 15 and the retainer 17, but they can be made separate therefrom and seemed in place by any suitable means;

The steam enters the machine through the conduit and innnediately'fills the annular chamber whence it passes through the nozales and acts on the buckets. Steam issuing from the buckets 1O enters the space within the inner wheel and freely passes through the spaces between the spokes of the retainers of both wheels into the exhaust chamber 20, the latter communicating with the conduit t which leads to a condenser of suitable construction. By reason of the construction described 1 am able to make the buckets 8 and 16 of such length and width as are necessary tohandle very large volumes of mo-.

tive fluid and it is evident that they maybe made longer or shorter as the requirements of the service demand.

In accordance with the provisions of the patent statutes, 1 have described the principle of operation of my invention, together with the apparatus which I now consider to represent the bestembodiment thereof but I desire to. have it" understood that theapparatus shown is only illustrative, and that they invention can be carried out by other means,

What I claim as new and desire to secure effectively prevents the.

'bination of-a ca'singcontaining by Letters'el atentl oft he United States,

ets mounted on the Wheels, separate shafts for the wheels, a retainin means for the ends of the buckets, and iametrically ere tending braces for the retainer which hold it against centril'u al forces. I

In. an elastic fluid turbine, the combine. tion of a casing, a wheel mounted therein, a shaft for the'whe'el, buckets supported" at one end by the .wheel and extending parallel with the shaft, and a retaining means for maintaining the unsupported portion of the buckets against centrifugal stresses, said hi ans comprising a ring, a hub, and radially-disposed connectors between the ring and hub.

In an elastic-..iuid turbine, the combination or" a casing, wheels mounted therein,

and located one within the other, axially extending buckets, individual shafts for the wheels, a retaining means for the ends of one set of buckets, diametrically extending braces for said means, and a hub to which the braces are connected, the said hubbein bored to receive one of the shafts'whic bore is larger than the shaft at. In an elastic-fluid turbine, the combination of a. casing, Wheels'rnountedtherein and located one Within the other,v axially extending buckets mounted on the wheels, oppositely extending shaits for the wheels,

a retainer for the ends of one set OfbUClIQtS rigidly supported by a shaft, a retainer: for

a second set of buckets, and diametrically extending braces for the retainer.

3. In an elastic fluid turbine, the combination of messing, wheels mounted therein, axially-extending buckets supported at one end by one of the Wheels, a retainer for maintaining the unsupported portion of the buckets against centrifugal stresses, and braces for said retainer which extend diametrically of the Wheel and are under tension when the same is rotating. 7

6. In an elastic-fluid turbine, the combination of acasing, Wheels located therein,

axial buckets mounted on th'e'wheels, individual shafts for the wheels, a ring uniting the ends of one row of buckets, and a return- 111g means therefor comprising an interlocking ring, radial spokesthat are under tension, and a hub which is connected to the spokes and is bored to'permit one of the shafts to pass through it Without engagement. I

7. In an elastic-fluid turbine, "the comcumferential chamber, an. inlet conduit nected to the chamber. nozzles receiving, motive fluid from the chamber, oppositely 'r o" ting wheels,-axia1 buckets carried by thew eels and propelled by the fluid from the nozzles,

retainers for the buckets of both wheels through which the exhaust passes, one: of the retainers being perforated to permit 5- shaft to pass freely through it, and an exhaust conduit.

8. In an elastic-fluid turbine, the coinbi'nation of a casing having an inlet and an outlet, oppositely rotating wheels mounted therein, shafts for the wheels extending in opposite directions, bearings for-the shaft-s located on opposite sides of the casing, axial buckets secured to the shafts, a retaining means for the ends of one set of buckets, which is carried by the same shaft that supports the buckets, a retaining means for the ends of the other set of buckets, and diametrically extendingubraces for the means which revolve freely Wlth respect to the other wheel- -and its shaft.

9. In an elastic fluid turbine, the combinatiornof a casing, oppositely rotating wheels mounted in the casing and located one within the other, axially-extending buckets carried by said wheels, diametrically extending braces for the outer ends of the buckets, a supply conduit, nozzles arranged adjacent the periphery of the outer JOHN A, MoMAN Us, Jr;, HENRY O. W sTr JxDARP. V 

